Circulation of liquids in preheaters and steam generators



July 24, 1928.

A.SCHNHDER CIRCULATION OF LIQUIDS IN PREHEATERS AND STEAM GENERATORS Filed Sept Fig.2

Fig.1

li atented July 24, 1928.

stares ADOLF SCHNEIDER, 0F KELEEEM, GER-MANY, ASSIGNOR 'lO NIED'ERBAYERISOHE CELLULOSEWERKE, OF KELZ'IEXBLON-THE-IDANUBE, GERMANY, A CORPORATION OF GERMANY.

CIRCULATION OF LIQUIDS IN FEE-HEATERS: AND STEAIYI GENERATORS.

Application filed September 28, 1825, Serial No. 59,119, and in Germany July 22, 1925.

The invention relates to means for improving the circulation 1n steam generators and preheating ClQVlCGS. by preventing the transmission of impulses, which would produce or tend to produce a backward flow, more particularly in the down-flow tubes of such generators. The invention can be applied to any type of preheater or steam generator in which these impulses are liable to occur, for example to Field tubes, boilers w'th inclined tubes, water tube boilers, or boilers consisting only of coiled tubes.

According to the invention, means are provided to reverse the direction of flow at some part of the flow or the medium to be heated or evaporated and anon-return valve is provided at this part which acts by its own weight to cut ott any impulses tending to set up a backward flow at any time in this circulating medium.

An example of an arrangement according to the invention is represented 1n the accompanying drawing as applied to a Field tube, in which Fig. lis a vertical cross-section of: the tube on line I-I of Fig. 3,

Fig. 2 is a vertical section on the line Il-ll otFig, 3,

Fig. 3 is a horizontal section on the line H1 H1 of Fig. 1.

Only the lower end of the Field tube is shown.

a, is the outer tube heated by the furnace gates in which the steam or the mixture of steam and water ascends, 7) is the inner down flow tube in which the water to be evaporated descends. At the lower end of this tube a cylindrical extension 0 which according to theinve-ntion contains the means for reversing the direction of flow of the water. The descending water flows into two oppositely disposed chambers (Z or" lenticular cross section. These chambers are connected below by openings 6 (l'li'g. 2) with two chambers f, 7 which can be shut oil from one another by a closing device, for example a ball 70 which rests on a valve seat 2'. The chamber 7 is closed above by av screw-threaded cover Z. The direction of flow oi the water is reversed in the chamher 7, it flows upwards, raises the ball 7c, enters into the upper chamber f and flows thence through openings 9 into two laterally arranged passages h which open below into the outer tube a. The rate of flow of the water into the tube a depends on the evaporation which occur? in this tube. Any backward impulses which might arise cannot be transmitted to the water in the tube 6, since in this case the ball lcwould in'nnediatel 1 fall by its own weight on its seat 2' and thereby protects the tube 6 from the pressure eXisting in the tube a.

The arrangement of rev 1g the flow of the water so that the down-now tube can be shut olii' from the up-tlow tube by the action of the weight of the closing device ensures a reliable action of this device in preventing any temporary pressure impulse from enteri the downdiow tube, and can be employed with any steam generator or preheater. (the medium to be preheated or evaporated may be a liquid, for example ;cr, or a gas.

Having thus described the nature of our said invention and the best means we know we clai1i'1:

1. In a steam generator, at prising an outer steam and water tube and an inner down flow tube, a chamber at the lower end of said down flow tube, the said chamber comprising compartments through which the liquid flows downwardly, an inner compartment in communication with said first-mentioned compartments and in which the direction of flow ot the liquid is reversed, a non-return valve in said inner compartment, and further compartments in said chamber through which the liquid descends into the outer steam and water tube.

In a steam generator, a Field tube comprising an outer steam and water tube and an inner down flow tub-e, said down flow tube having a downwardly directed cylindrical extension, chambers in said extension down which the liquid descends, a chamber extending upwards from the base of said cylindrical extension and communicating with said first-mentioned chambers, a seating in said chamber, and a ball adapted to rest by its weight on said seating, the wall of said chamber having lateral passages above said seating and communicating with said outer steam and water tube.

In testimony whereof l have signed my name to this specification.

ADOLF SCHNEIDER.

ot' carrving the same into practical effect,

Field tube com- 

